ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Sensitivity of PSA process performance to input variables (1995)
    Springer
    Adsorption 1 (1995), S. 133-151 
    Details
    ISSN: 1572-8757
    Keywords: PSA process ; sensitivity ; equilibria ; kinetics ; heats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Mathematical models for pressure swing adsorption (PSA) processes essentially require the simultaneous solutions of mass, heat and momentum balance equations for each step of the process using appropriate boundary conditions for the steps. The key model input variables needed for estimating the separation performance of the process are the multicomponent adsorption equilibria, kinetics and heats of adsorption for the system of interest. A very detailed model of an adiabatic Skarstrom PSA cycle for production of high purity methane from a ethylene-methane bulk mixture is developed to study the sensitivity of the process performance to the input variables. The adsorption equilibria are described by the heterogeneous Toth model which accounts for variations of isosteric heats of adsorption of the components with adsorbate loading. A linear driving force model is used to describe the kinetics. The study shows that small errors in the heats of adsorption of the components can severely alter the overall performance of the process (methane recovery and productivity). The adsorptive mass transfer coefficients of the components also must be known fairly accurately in order to obtain precise separation performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705001
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Frequency response analysis of a closed diffusion cell with two resonators (1996)
    Springer
    Adsorption 2 (1996), S. 265-277 
    Details
    ISSN: 1572-8757
    Keywords: frequency response ; diffusion cell ; kinetics ; diffusion ; heat effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper deals with frequency response (FR) analysis of a closed diffusion cell system with two resonators, that is both the LHS and RHS volumes are modulated. The analysis is made for a homogeneous particle described by a single effective diffusivity as well as a biporous pellet described by macropore and micropore diffusions. It is shown that if the perturbation of the volume of the reservoir #2 is lagged behind that of the reservoir #1 by 3π/2, the pressure response in reservoir #1 is significantly enhanced with larger amplitude as well as phase angle. When the perturbations of the two reservoirs are out of phase, the heat effect is reduced and can become insignificant when the two perturbations are completely out of phase (ψ = π). Under such a condition, the pressure difference between the two reservoirs could be doubled. In the case of biporous pellets, it is shown that the FR behaviours obtained for micropore diffusion control and macropore diffusion control are well distinguished. In the former case, the FR system reduces to a traditional batch adsorber one while in the latter case, the FR behaviour is the same as for a two resonator system with homogeneous particles. This difference can be used for the discrimination of micropore and macropore diffusion processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00879541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Equilibria and kinetics characterisation of two different structured nutshell-derived activated carbons (1997)
    Springer
    Adsorption 3 (1997), S. 267-275 
    Details
    ISSN: 1572-8757
    Keywords: characterisation ; equilibria ; kinetics ; micropore size distribution ; n-butane ; nutshell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption equilibria and dynamics ofn-butane on two activated carbon samples prepared from the physical activation of nutshell are studied in this paper. The micropore size distribution (MPSD) is considered as the main source of solid heterogeneity. Lennard-Jones' potential theory and Dubinin's theory (TVFM) are used in the equilibria data to derive the MPSD, which is well fitted by a Gamma distribution function. The adsorption energy distribution derived from the MPSD is very asymmetric for both the samples studied, and this energy distribution used in the HMSD/HMSMD kinetics models for the study of adsorption dynamics ofn-butane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01653629
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Pure and Binary Gas Adsorption Equilibria and Kinetics of Methane and Nitrogen on 4A Zeolite by Isotope Exchange Technique (1999)
    Springer
    Adsorption 5 (1999), S. 145-158 
    Details
    ISSN: 1572-8757
    Keywords: kinetics ; isotope-exchange ; nitrogen ; adsorption ; methane ; zeolite ; equilibria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Isotope Exchange Technique (IET) was used to simultaneously measure pure and binary gas adsorption equilibria and kinetics (self-diffusivities) of CH4 and N2 on pelletized 4A zeolite. The experiment was carried out isothermally without disturbing the adsorbed phase. CH4 was selectively adsorbed over N2 by the zeolite because of its higher polarizability. The multi-site Langmuir model described the pure gas and binary adsorption equilibria fairly well at three different temperatures. The selectivity of adsorption of CH4 over N2 increased with increasing pressure at constant gas phase composition and temperature. This curious behavior was caused by the differences in the sizes of the adsorbates. The diffusion of CH4 and N2 into the zeolite was an activated process and the Fickian diffusion model described the uptake of both pure gases and their mixtures. The self-diffusivity of N2 was an order of magnitude larger than that for CH4. The pure gas self-diffusivities for both components were constants over a large range of surface coverages (0 〈 θ 〈 0.5). The self-diffusivities of CH4 and N2 from their binary mixtures were not affected by the presence of each other, compared to their pure gas self-diffusivities at identical surface coverages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008917308002
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Prediction of paper permanence by accelerated aging I. Kinetic analysis of the aging process (1996)
    Springer
    Cellulose 3 (1996), S. 243-267 
    Details
    ISSN: 1572-882X
    Keywords: aging tests ; cellulose degradation ; durability ; kinetics ; paper properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The validity of accelerated aging tests to predict and rank papers on their permanence has been under question, preventing the development of performance-based standards for permanent paper. We conducted a general kinetic analysis to investigate the aging process of paper. A general kinetic model is proposed to describe the depolymerization of cellulose. Experimentally it was shown that in the case of aging, cellulose degradation follows classic first-order kinetics as a special case of our general kinetic model. The Arrhenius equation was critically re-examined for the case of a multiple reaction system. It was shown analytically that the Arrhenius equation is still applicable when certain conditions are met. This was convincingly supported by experimental results. We also analysed the dependence of the degradation rate on the moisture content and hydrogen ion concentration. By conducting systematic experiments on these two factors, a general and quantitative relationship was established to explain the contribution of each factor and their interactions. Finally, based on this kinetic analysis, the effects of storage conditions on the life expectancy of paper were estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02228805
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    On the kinetics of degradation of cellulose (1997)
    Springer
    Cellulose 4 (1997), S. 1-5 
    Details
    ISSN: 1572-882X
    Keywords: paper ; degradation ; ageing ; kinetics ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018408515574
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Prediction of paper permanence by accelerated aging II. Comparison of the predictions with natural aging results (1996)
    Springer
    Cellulose 3 (1996), S. 269-279 
    Details
    ISSN: 1572-882X
    Keywords: accelerated tests ; aging tests ; cellulose degradation ; durability ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Accelerated aging tests are credible and useful to predict paper permanence only if such tests can be shown to correlate with natural aging. In the first part of this study, a kinetic model was developed based on the accelerated aging results. In this report, we have shown that this kinetic model can indeed predict the natural aging results of lignin-free sheets with a statistical confidence. This is the first quantitative comparison of accelerated aging with natural aging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02228806
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Kinetics and mechanisms of the low-temperature degradation of cellulose (1994)
    Springer
    Cellulose 1 (1994), S. 26-56 
    Details
    ISSN: 1572-882X
    Keywords: low-temperature degradation ; kinetics ; mechanisms ; electrical insulation ; transformers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A critical review is given of the degradation of cellulose in the low-temperature region (below about 300°C) of power transformer operation. The large number of kinetic studies, under a variety of environmental conditions from Kraft paper in insulating oil, to cotton and paper in oxygen, are considered in terms of a first-order polymer chain scission model. In many cases, the data are replotted to suit the model. A common activation energy of 111±6 kjmol−1 is calculated and it is shown that the pre-exponential factor, rather than the activation energy, is sensitive to the oxidizing nature of the environment and the susceptibility to degradation of the material. The chemical mechanisms of degradation are reviewed, and conclusions and recommendations are made regarding chemical condition monitoring and life prediction of electrical insulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00818797
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Sorption Equilibria and Kinetics of Hydrocarbons onto Activated Carbon Samples Having Different Micropore Size Distributions (1999)
    Springer
    Adsorption 5 (1999), S. 25-37 
    Details
    ISSN: 1572-8757
    Keywords: micropore size distribution ; activated carbon ; adsorption ; desorption ; equilibrium ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper deals with the prediction of adsorption equilibrium and kinetics of hydrocarbons onto activated carbon samples having different micropore size distribution (MPSD). The microporous structure of activated carbon is characterised by the distribution of slit-shaped micropores, which is assumed to be the sole source of surface heterogeneity. The interaction between adsorbate molecule and pore walls is described by the Lennard-Jones potential theory. Different adsorbates have access to different pore size range of activated carbon due to the size exclusion, a phenomenon could have a significant influence on both multicomponent equilibria and kinetics. Activated carbons with three different MPSDs are studied with ethane and propane as the two model adsorbates. The Heterogeneous Macropore Surface Diffusion model (HMSD) is employed to simulate adsorption kinetics. The simulation results show that the MPSD is an important factor affecting both the multicomponent equilibria and kinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026481704926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Static and Kinetic Studies on the Adsorption Behavior of Sulfadiazene (2000)
    Springer
    Adsorption 6 (2000), S. 349-357 
    Details
    ISSN: 1572-8757
    Keywords: sulfadiazene ; adsorption ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract To investigate the nature of interactive forces between sulfadiazene molecules and alumina surface the experiments were performed for the adsorption of sulfadiazene (SD) from its aqueous sulution onto the alumina surfaces at 25 ± 0.2°C and the influence of factors such as increasing concentration of SD (4.0–20.0 × 10−3 mol cm−3), the time required for adsorption equilibrium, pH (2.0–12.0) and temperature (5–45°C) of the adsorption medium, the presence of ions like Cl−, SO2− 4 and PO3− 4 (0.01–0.30 M) and organic solvents (5% v/v) were observed on the course of adsorption of SD. Various adsorption and kinetic parameters such as adsorption coefficient, the rate constants for adsorption and desorption were also evaluated. The results of the above cited studies facilitated to formulate the mechanisms of interaction between SD and alumina surfaces. From application view point the present work may be a potential tool for an effective chromatographic separation of sulfa drugs from industrial effluents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026517117239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Why Does the Linear Driving Force Model for Adsorption Kinetics Work? (2000)
    Springer
    Adsorption 6 (2000), S. 137-147 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; kinetics ; linear driving force model ; process design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Linear Driving Force (LDF) model for gas adsorption kinetics is frequently and successfully used for analysis of adsorption column dynamic data and for adsorptive process designs because it is simple, analytic, and physically consistent. Yet, there is a substantial difference in the characteristics of isothermal batch uptake curves on adsorbent particles by the LDF and the more rigorous Fickian Diffusion (FD) model. It is demonstrated by using simple model systems that the characteristics of the adsorption kinetics at the single pore or the adsorbent particle level are lost in (a) evaluating overall uptake on a heterogeneous porous solid, (b) calculating breakthrough curves from a packed adsorbent column, and (c) establishing the efficiency of separation by an adsorptive process due to repeated averaging of the base kinetic property. That is why the LDF model works in practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008965317983
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    The kinetics and regulation of M-xylose transport in Candida utilis (1993)
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 357-360 
    Details
    ISSN: 1573-0972
    Keywords: Candida utilis ; inhibition ; kinetics ; regulation ; sugar ; transport ; xylose ; yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Low-affinity (K m=67.6±3.2 mM) and high-affinity (K m=1.9±1.2 mM) D-xylose transport occur in Candida utilis grown, respectively, on D-glucose or D-xylose. Starvation of glucose-grown cells decreases the K m value (10.5±2.6 mm). The high-affinity system appearing during starvation required protein synthesis and it was inactivated when cells were exposed to glucose, by a process independent of protein synthesis. High-affinity transport was accompanied by transient alkalinization of yeast suspensions, indicating that it is a proton symport, whereas low-affinity transport was not. Both systems, however, were inhibited by metabolic inhibitors and by replacing H2O in the transport assay with D2O, indicating that both may be proton symports. Glucose and acetic acid also inhibited both high-and low-affinity xylose transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00383080
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Interaction of dichloromethane (methylene chloride) with the nitrous oxide reductase from Wolinella succinogenes (1993)
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 479-482 
    Details
    ISSN: 1573-0972
    Keywords: Benzyl viologen ; dichloromethane ; inhibitor ; kinetics ; nitrous oxide ; nitrous oxide reductase ; tetrachloromethane ; trichloromethane ; Wolinella succinogenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Nitrous oxide reductase from Wolinella succinogenes was tested for benzyl viologen cation (BV+)-chlorinated methane oxidoreductase activity, using di-, tri- and tetra-chloromethanes, and for the inhibition of BV+-N2O oxidoreductase activity by these chloromethanes. No BV+-chlorinated methane oxidoreductase activity was detected. Any such activity, if it exists, must be less than 0.1% of the BV+-N2O oxidoreductase activity of the enzyme. Inhibition of the BV+-N2O oxidoreductase activity by dichloromethane was detected and was apparently reversible and non-competitive, as is the case with the small metal-ligand type inhibitors of the enzyme (e.g. acettlene, azide, cyanide and carbon monoxide). Trichloromethane was a weaker inhibitor and inhibition was not detected with tetrachloromethane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328037
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Chlorine decay and bacterial inactivation kinetics in drinking water in the tropics (1996)
    Springer
    World journal of microbiology and biotechnology 12 (1996), S. 549-556 
    Details
    ISSN: 1573-0972
    Keywords: Bacteria inactivation ; chlorine decay ; combined chlorine ; drinking water ; free chlorine ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The decay of free chlorine (Cl2) and combined chlorine (mostly monochloramine: NH2Cl) and the inactivation of bacteria was examined in Dar es Salaam, Tanzania. Batch experiments, pilot-scale pipe experiments and full-scale pipe experiments were carried out to establish the kinetics for both decay and inactivation, and to compare the two disinfectants for use under tropical conditions. The decay of both disinfectants closely followed first order kinetics, with respect to the concentration of both disinfectant and disinfectant-consuming substances. Bacterial densities exhibited a kinetic pattern consisting of first order inactivation with respect to the density of the bacteria and the concentration of the disinfectant, and first order growth with respect to the bacterial density. The disinfection kinetic model takes the decaying concentration of the disinfectant into account. The decay rate constant for free chlorine was 114 lg-1h-1, while the decay rate constant for combined chlorine was 1.84 lg-1h-1 (1.6% of the decay rate for free chlorine). The average concentration of disinfectant consuming substances in the water phase was 2.6 mg Cl2/l for free chlorine and 5.6 mg NH2Cl/l for combined chlorine. The decay rate constant and the concentration of disinfectant consuming substances when water was pumped through pipes, depended on whether or not chlorination was continuous. Combined chlorine especially could clean the pipes of disinfectant consuming substances. The inactivation rate constant λ, was estimated at 3.06×104 lg-1h-1. Based on the inactivation rate constant, and a growth rate constant determined in a previous study, the critical concentration of free chlorine was found to be 0.08 mg Cl2/l. The critical concentration is a value below which growth rates dominate over inactivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00419471
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Growth characteristics of Geotrichum ingens on propionic acid and acetic acid in batch and continuous culture (1994)
    Springer
    World journal of microbiology and biotechnology 10 (1994), S. 505-509 
    Details
    ISSN: 1573-0972
    Keywords: Acetic acid ; chemostat ; Geotrichum ingens ; growth ; inhibition ; kinetics ; monocarboxylic acids ; propionic acid ; yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Growth of Geotrichum ingens in batch cultures was completely inhibited by 47 g acetic acid/l or 33 g propionic acid/I. With mixtures of acetic and propionic acids, however, growth only ceased at 55 g/l. Acetic acid inhibited growth linearly, whereas propionic acid inhibited growth non-linearly. In continuous culture, two steady states at each dilution rate were observed at high dilution rates for acetic acid and propionic acid. The highest yield coefficient (0.69 g cells/g substrate) was achieved with propionic acid as substrate. On both substrates and their mixtures, the protein content of the biomass increased when the dilution rate was increased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367654
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    A weighing method to identify the microbial growth phases in solid-state fermentation tests (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 601-605 
    Details
    ISSN: 1573-0972
    Keywords: Growth phases identification ; kinetics ; Rhizopus oryzae ; solid-state fermentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A general equation correlating the variation rate of the fermenting medium weight (dry matter) and the cell biomass growth rate in solid-state fermentation tests is proposed with the main purpose of identifying the microbial growth phases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008970720794
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Hybridomas in a bioreactor cascade: modeling and determination of growth and death kinetics (1996)
    Springer
    Cytotechnology 21 (1996), S. 263-277 
    Details
    ISSN: 1573-0778
    Keywords: hybridomas ; serum-free medium ; monoclonal antibodies ; reactor series ; kinetics ; modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Hybridomas were cultured under steady-state conditions in a series of two continuous stirred-tank reactors (CSTRs), using a serum-free medium. The substrate not completely converted in the first CSTR, was transported with the cells to the second one and very low growth rates, high death rates, and lysis of viable cells were observed in this second CSTR. These conditions are hardly accessible in a single vessel, because such experiments would be extremely time-consuming and unstable due to a low viability. In contrast to what is often observed in literature, kinetic parameters could thus be derived without the neccessity for extrapolation to lower growth rates. Good agreement with literature averages for other hybridomas was found. Furthermore, showing that the reactor series is a valuable research tool for kinetic studies under extreme conditions, the possibility to observe cell death under stable and defined steady-state conditions offers interesting opportunities to investigate apoptosis and necrosis. Additionally, a model was developed that describes hybridoma growth and monoclonal antibody production in the bioreactor cascade on the basis of glutamine metabolism. Good agreement between the model and the experiments was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Comparison of specific rates of hybridoma growth and metabolism in batch and continuous cultures (1992)
    Springer
    Cytotechnology 10 (1992), S. 147-155 
    Details
    ISSN: 1573-0778
    Keywords: batch culture ; continuous culture ; hybridoma ; kinetics ; specific rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract For the mouse hybridoma cell line VO 208, kinetics of growth, consumption of glucose and glutamine, and production of lactate, ammonia and antibodies were compared in batch and continuous cultures. At a given specific growth rate, different metabolic activities were observed: a 40% lower glucose and glutamine consumption rate, but a 70% higher antibody production rate in continuous than in batch culture. Much higher metabolic rates were also measured during the initial lag phase of the batch culture. When representing the variation of the specific antibody production rate as a function of the specific growth rate, there was a positive association between growth and antibody production in the batch culture, but a negative association during the transient phase of the continuous culture. The kinetic differences between cellular metabolism in batch and continuous cultures may be result of modifications in the physiology and metabolism of cells which, in continuous cultures, were extensively exposed to glucose limitations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00570891
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Effect of hypoxia duration on the oxygen-dependent production of a recombinant protein, β-galactosidase, by an animal cell line, F6D2, with a hypoxia-inducible enhancer (1997)
    Springer
    Cytotechnology 25 (1997), S. 71-77 
    Details
    ISSN: 1573-0778
    Keywords: hypoxia ; recombinant protein ; animal cells ; erythropoietin ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Expression of specific genes is a strategy of animal cells for adaptation to oxygen deficiency and the mechanism underlying the hypoxic activation of gene expression may be useful for efficient production of recombinant proteins by animal cells, because oxygen is a limiting factor in animal cell cultures. We prepared an animal cell line harboring the plasmid in which expression of a reporter gene, β-galactosidase, is controlled by an enhancer responsible for the hypoxic activation of gene transcription. The purpose of this paper is to understand this hypoxic production of recombinant proteins quantitatively by a mathematical model originally developed based on the following hypotheses; 1 lacZ (the reporter gene) is transcribed after HIF-1 protein complex is bound to the hypoxic enhancer, 2. β-galactosidase synthesis rate is limited at the transcription of lacZ, 3. HIF-1 is an inactive form under a normal oxygen concentration, 4. Oxygen works as a repressor in the synthesis of HIF-1 protein, 5. Both β-galactosidase and HIF-1 are decomposed according to the first order reaction. The effects of hypoxic duration as well as oxygen concentration on the β-galactosidase production were successfully predicated by the model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007911816292
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Influence of inoculum age on hybridoma culture kinetics (1991)
    Springer
    Cytotechnology 5 (1991), S. 165-171 
    Details
    ISSN: 1573-0778
    Keywords: growth ; hybridoma ; inoculum age ; kinetics ; production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract To determine the influence of the inoculum age on the kinetics of hybridoma growth and metabolism, spinner flasks have been inoculated with cells previously propagated in T flasks for 43, 52, 62 and 71 hr respectively. Increasing the age of the inoculum is found to result in a longer lag phase, in a lower maximum specific growth rate and in a reduced maximal cell density. During the growth phase specific rates of glucose and glutamine uptake and of ammonia and lactate production are similar. However, with the older inoculum, much higher metabolic activities are observed during the lag phase. The production of antibodies is delayed with increasing inoculum age, but the final antibody concentrations are similar, which indicates a higher specific antibody production rate when inoculating with older cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365433
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Growth and protein production kinetics of a murine myeloma cell line transfected with the human growth hormone gene (1991)
    Springer
    Cytotechnology 5 (1991), S. 223-231 
    Details
    ISSN: 1573-0778
    Keywords: cell culture ; kinetics ; Ig promoter/enhancer ; plasmacytoma ; recombinant protein production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A model mammalian cell system for the production of recombinant proteins was investigated. Murine myeloma cells which had lost the ability to produce both heavy and light chain immunoglobulin molecules were transfected with a vector containing the immunoglobulin heavy chain promoter and enhancer elements linked to the human growth hormone gene. The growth kinetics of G32, a clonal isolate, were found to be similar to both the parent myeloma and hybridomas. However, production of hGH by G32 was growth associated, rather than as a secondary metabolite as is the case for hybridomas. In addition, G32 produced hGH at molar levels greater than most hybridomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00556292
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...